1. Field of the Invention
The present invention relates to a novel superoxide dismutase (hereinafter referred to as "SOD") and a process for the preparation thereof.
2. Description of the Related Art
SOD is an enzyme disproportionating two superoxide radicals into a hydrogen peroxide and a molecular oxygen, and it is known that SOD is widely present in animals, plants and microorganisms. The superoxide radical is an important agent of toxity of oxygen generated in an organism, and it is understood that SOD protects an organism from the superoxide radical have been recently elucidated, and the role of SOD as the organism defending enzyme has attracted attention. For example, it has been found that SOD effectively protects against oxidation easily oxidizable substances such as foodstuffs (Japanese Unexamined Patent Publication No. 5-40785), as a cosmetic component for protecting the skin and hair, controlling pigmentation on the skin, exerting an anti-inflammatory action to the skin and preventing putrefaction of components of a cosmetic composition (Japanese Unexamined Patent Publications No. 51-63949 and No. 55-87712) and for the remedy of rheumatoid arthritis (M. Walravents & J. Dequeker, Current Therapeutic Res., 20 62-69, 1976).
SOD is a metal-containing enzyme and is divided into three types, copper (Cu)-zinc (Zn)-SOD, manganese (Mn)-SOD, and iron (Fe)-SOD, according to the kind of metal contained therein. It is known that Cu, Zn-SOD is present in the cytoplasm of eucaryotes, Mn-SOD is present in the mitochondria of eucaryotes, algae and prokaryotic cells, and Fe-SOD is present in algaes and prokaryotic cells. However, the SOD of the present invention has not been known.